This multicenter trial is testing the safety and efficacy of weekly administration of antenatal steroids. Twenty four hundred women < 32.0 weeks gestation who are at risk for spontaneous preterm delivery and remain pregnant at least seven days after an initial course of corticosteroids are being randomized to either weekly courses of masked study drug (betamethasone or placebo) for 4 weeks or delivery, whichever comes first. Patients are asked about side effects at the weekly visits and samples of maternal blood at randomization and delivery are collected. Cord blood and placentas are also collected. Cranial ultrasounds are done on all neonates. On a subgroup of patients, an adrenocorticotrophic hormone (ACTH) stimulation test is being performed and an auditory brainstem response (ABR) performed. All infants attend a follow-up visit at 18 to 22 months corrected age where certified examiners, masked to study group assignment, collect physical and neurological data. The Bayley Scales of Infant Development will also be administered. A subgroup of infants will be seen at 36 months to administer the Intelligence scale from the McCarthy Scales of Children's Abilities.